Organic compounds include many optical isomers having completely the same physical, chemical properties, for example, properties such as boiling point, melting point, solubility but showing different physiological activities. In the technical field of medicaments, differences in the pharmacological activity depending on the easiness of binding with a particular receptor in the body have been studied much, and it is widely known that remarkable differences in drug efficacy and toxicity are often found between optical isomers. Guideline for drug production by the Ministry of Health, Labour and Welfare also describes that it is desirable to study absorption, distribution, metabolism and excretion kinetics of each isomer when a racemate is used as a drug.
As described above, since optical isomers show completely the same physical and chemical properties, they cannot be analyzed by general separation means. Thus, the study of techniques for easily and precisely analyzing optical isomers of a wide variety of organic compounds has been extensively conducted. Of such techniques, particularly, the optical resolution method by high performance liquid chromatography (hereinafter sometimes to be also referred to as HPLC) separates optical isomers by using a substance having an ability to separate optical isomers, i.e., an optical isomer separating agent, per se, or a chiral stationary phase supporting an optical isomer separating agent on a suitable carrier by a chemical bond or coating. For example, a packing material comprising an optically active crown ether compound, which is a low-molecular-weight compound, coated on a carrier (patent document 1), a packing material comprising an optically active triphenylmethyl methacrylate polymer, which is a synthetic polymer, coated on a carrier (patent document 2), a packing material comprising cellulose triacetate, which is a polysaccharide derivative, coated on a carrier (patent document 3), a packing material comprising cellulose benzoate coated on a carrier (patent document 4), a packing material comprising cellulose phenylcarbamate coated on a carrier (patent document 5), a packing material comprising a cellulose or amylose derivative (non-patent document 1), ovomucoid which is a protein (patent document 6) and the like have been developed and, in view of their high optical resolution ability, commercialized and widely used.